Yes ECC6.0 comes with complete PLM solution ,may be some components you need to activate with separate licensining agreement.
In PLM implementation Basis person has to create and maintain roles for PLM users. Also if you use EP components in PLM implementation then the server administration will be managed by Basis consultant.
Some PLM modules as DMS,contenet server management and configuration is responsibility of Basis person.
So basically all PLM roles and server maintainace is done by Basis.
I hope this will help to get info about your question.
